Exposure process and photomask set used therein
AssigneeMacronix International Co., Ltd.
InventorsChih-Hao Huang, Chin-Cheng Yang
Life of this patent
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Abstract
An exposure process is described, for defining in a photoresist layer a plurality of first patterns having a first pitch and a second pattern between them that is wider than one first pattern. A first exposure step is conducted to the photoresist layer with a first photomask that has a plurality of the first patterns without a second pattern between them, wherein the first patterns on the first photomask have the first pitch only. A second exposure step is conducted to the photoresist layer with a second photomask that has a third pattern narrower than the second pattern at a position corresponding to the second pattern. The exposure dose of the first or second exposure step alone is not sufficient to define any pattern in the photoresist layer.
Claims18
An exposure process for defining, in a photoresist layer, a plurality of first patterns having a first pitch and a second pattern between the first patterns that is wider than one first pattern, comprising:
- conducting a first exposure step to the photoresist layer with a first photomask, which has a plurality of the first patterns without the second pattern between them, wherein the first patterns on the first photomask have the first pitch only;
- and
- conducting a second exposure step to the photoresist layer with a second photomask, which has a third pattern narrower than the second pattern at a position corresponding to the second pattern,
- wherein an exposure dose of the first or second exposure step alone is not sufficient to define any pattern in the photoresist layer.
An photomask set for defining in an exposure process a plurality of first patterns having a first pitch and a second pattern between the first patterns that is wider than one first pattern, comprising:
- a first photomask that has a plurality of the first patterns without the second pattern between them, the first patterns on the first photomask having the first pitch only;
- and
- a second photomask that has a third pattern narrower than the second pattern at a position corresponding to the second pattern.
Dependencies are inferred from the claim text.